package gaobo.queue;

//环形队列【力扣622】
public class MyCircularQueue {

    private int[] elem;
    public int front;//队头
    public int rear;//队尾

    public MyCircularQueue(int k){
        elem = new int[k+1];
    }
    //入队列
    public boolean enQueue(int value){
        if (isFull()){
            return false;
        }
        elem[rear] = value;
        rear = (rear + 1) % elem.length;
        return true;
    }

    //浪费一个空间判断满
    public boolean isFull(){
        if ((rear + 1) % elem.length == front){
            return true;
        }
        return false;
    }
    //出队列
    public boolean deQueue(){
        if (isEmpty()){
            return false;
        }
        front = (front + 1) % elem.length;
        return true;
    }

    public boolean isEmpty(){
        if (front == rear){
            return true;
        }
        return false;
    }
    //获取队头元素
    public int Front(){
        if (isEmpty()){
            return -1;
        }
        return elem[front];
    }
    //获取队尾元素
    public int Rear(){
        if (isEmpty()){
            return -1;
        }
        int index = rear == 0 ? elem.length-1 : rear-1;
        return elem[index];
    }

}
